clay how to warm

I often use a crock to warm my clay, the type for turkeys -larger , then I keep an aluminum type tin inside, and put the clay in this. To keep clean or if I need to use another clay. You need to keep low heat, try different heat settings to see which works best for you.
You can heat in a microwave -be careful, you can burn your fingers.

oil based clay to use

I use Klean Clay for my sculptures. You can order at sculpt.com or other places. I order directly from the company that makes the clay.
Reason for this- I use grey clay-ex-firm, You cannot buy the grey clay in ex-firm unless you ask for a order from the company, you have to buy 350 lbs.
I think it is worth it for the money you save in the long run.
You of course can re-use the oil-based clay over and over again.

after you made the mold, for figure sculpture, portrait sculptor

After you made the mold or (mould) if things did not work out exactly as you would have liked?
I often cast in plaster- I made corrections when things did not come out perfectly-

1. don't forget to wet the plaster before you apply new plaster.
2. you can keep the plaster thin- for the small holes and wipe off extra plaster
3. thicker plaster can work well for bigger areas to replace or rebuild

if you have questions let me know